JP6000170B2 - Electronics - Google Patents

Description

  The present invention relates to an electronic device having vibration resistance performance, electromagnetic shielding performance, and heat dissipation performance.

  Electronic devices are required to have vibration resistance, electromagnetic shielding performance and heat dissipation performance. In addition, there is a demand for an increase in the component mounting area on the substrate in order to reduce the size and weight.

  Conventionally, an electromagnetic shield is made of a highly rigid sheet metal member, and a heat radiating member is fixed to the sheet metal member to satisfy electromagnetic shielding performance and heat radiation performance. However, if the thickness of the sheet metal member is increased so as to support the heat radiating member, the weight increases, and in order to satisfy the vibration resistance, it is necessary to increase the area for fixing and grounding the sheet metal member to the substrate. Therefore, there is a problem that the component mounting area on the substrate is reduced.

  Further, for example, in Patent Document 1, two insulating heat dissipation sheets are attached with an electromagnetic shield in between, heat generated in an electronic component is transmitted to the electromagnetic shield through the insulating heat dissipation sheet, and another sheet is released from the electromagnetic shield. It was conveyed to the module case via the insulating heat dissipation sheet. In the case of this configuration, if the heat radiating member is fixed to the module case, the thickness of the electromagnetic shield can be reduced and the weight can be reduced. Therefore, it is not necessary to increase the grounding area of the electromagnetic shield. However, since there are more members interposed between the electronic component and the heat dissipation member, there is a problem that the heat dissipation performance is deteriorated as compared with the above structure.

Japanese Patent Laid-Open No. 10-41678

  Since the conventional electronic device is configured as described above, there is a problem that it is difficult to reduce the fixing (grounding) area of the electromagnetic shield while satisfying the vibration proof performance, the electromagnetic shield performance, and the heat dissipation performance. For this reason, it has been difficult to reduce the size and weight of electronic devices.

  The present invention has been made to solve the above-described problems. Even if the electromagnetic shield fixing (grounding) area is reduced, an electronic device satisfying the same vibration resistance performance, electromagnetic shielding performance, and heat radiation performance as in the past. The purpose is to provide equipment.

  An electronic device according to the present invention includes a board on which an electronic component is mounted, a chassis that houses the board, a heat conduction component provided on an upper end surface of the electronic component, and an electronic device that is fixed to the chassis and is interposed via the heat conduction component. A heat dissipating component that contacts the upper end surface of the component, and an electromagnetic shielding component that surrounds the side of the electronic component, has a lower end fixed to the substrate, and an upper end that elastically contacts the heat dissipating component.

  According to the present invention, the heat radiation component covering the upper end surface side of the electronic component is fixed to the chassis, and the electromagnetic shield component covering the side of the electronic component is brought into elastic contact with the heat radiation component. There is no need to support heat dissipation parts, and the electromagnetic shield parts can be made thinner and lighter. As a result, the area of fixing (grounding) between the electromagnetic shield component and the substrate can be reduced, and the area of the substrate can be expected to be reduced. In addition, since the electronic component and the heat radiating component can be brought into direct contact with each other through the heat conducting component, the heat radiating component can be reduced in size by improving the heat radiating effect. Because of these effects, even if the grounding area for fixing electromagnetic shielding components to the board is reduced, the same vibration resistance, electromagnetic shielding performance, and heat dissipation performance can be satisfied, and the entire electronic device can be reduced in size and weight. Become.

It is a schematic diagram which shows the cross-section of the electronic device which concerns on Embodiment 1 of this invention. It is a figure explaining the fixing method of the electromagnetic shielding component of the electronic device which concerns on Embodiment 1, FIG. 2 (a) is an enlarged view of a clip, FIG.2 (b) is an enlarged view of a to-be-fastened piece and a screw. 1 is an exploded perspective view illustrating a configuration example of an electronic device according to a first embodiment. It is a top view of the state which removed the upper chassis and the heat radiating component from the electronic device of FIG. It is a schematic diagram which shows the cross-section of the electronic device which concerns on Embodiment 2 of this invention. It is a schematic diagram which shows the cross-section of the electronic device which concerns on Embodiment 3 of this invention, and is the example which attached the axial flow fan. It is a schematic diagram which shows the cross-section of the electronic device which concerns on Embodiment 3, and is the example which attached the sirocco fan. FIG. 10 is an exploded perspective view illustrating a configuration example of an electronic device according to a third embodiment. FIG. 9A shows a configuration of the electronic device of FIG. 8, FIG. 9A is a plan view, and FIG. 9B is a cross-sectional view taken along line AA. It is a schematic diagram which shows the modification of the electronic device which concerns on this invention. It is a schematic diagram which shows another modification of the electronic device which concerns on this invention.

Embodiment 1 FIG.
The electronic device shown in FIG. 1 includes an electronic component 1 that generates heat, a substrate 2 on which the electronic component 1 is mounted, a lower chassis 3 that fixes the substrate 2, and an upper chassis 4 that is stacked on the lower chassis 3. . The lower chassis 3 and the upper chassis 4 are made of sheet metal such as iron.

  In this electronic apparatus, a heat radiating component 5 such as a heat sink is attached at a position facing the electronic component 1 of the upper chassis 4. The heat radiating component 5 is made of a conductive material having a high thermal conductivity, such as aluminum, and has a protruding portion 5a that protrudes toward the electronic component 1 side. Further, a heat conduction component 8 made of a material having high heat conductivity such as a heat conduction rubber is provided on the upper end surface of the electronic component 1.

  On the other hand, an electromagnetic shielding component 6 that covers the electronic component 1 is installed on the substrate 2. The electromagnetic shielding component 6 is made of an electromagnetic shielding material such as iron. On the upper end surface of the electromagnetic shielding component 6, an opening 6 a through which the protrusion 5 a of the heat dissipation component 5 passes and a plurality of leaf springs 6 b that elastically contact the heat dissipation component 5 are formed. Further, the lower end portion of the electromagnetic shield component 6 is sandwiched and grounded by a metal clip 7 fixed to the substrate 2. FIG. 2A shows an enlarged view of the clip 7.

  When the lower chassis 3 and the upper chassis 4 are joined together, the heat dissipating component 5 on the upper chassis 4 side and the electromagnetic shielding component 6 on the lower chassis 3 side are in elastic contact with each other by a plurality of leaf springs 6b. It is pressed down from. Further, the protrusion 5 a of the heat radiating component 5 enters the inside of the electromagnetic shielding component 6 through the opening 6 a of the electromagnetic shielding component 6, and contacts the upper end surface of the electronic component 1 through the heat conducting component 8. The heat generated by the electronic component 1 is transmitted to the heat radiating component 5 through the heat conducting component 8 and is radiated from the heat radiating component 5.

In the case of Patent Document 1 described in advance, a heat conduction component is attached to each of the front and back surfaces of the electromagnetic shield component, and the heat generated by the electronic component is transmitted to one of the heat conduction component, the electromagnetic shield component, the other heat conduction component, and the heat dissipation component. We told in order and radiated heat.
On the other hand, in the first embodiment, the electromagnetic shield component 6 is formed with the opening 6a, and the protruding portion 5a of the electronic component 1 and the heat dissipation component 5 is brought into contact via the heat conducting component 8. There are few members interposed between the electronic component 1 and the heat dissipation component 5, and the heat dissipation performance is improved. Therefore, even if the heat radiating component 5 is reduced in size and weight, the heat radiation performance equivalent to the conventional one can be ensured.

  In the first embodiment, the opening 6 a is formed in the electromagnetic shield component 6, but the opening 6 a is closed by the heat dissipation component 5. Further, since the peripheral edge of the opening 6a is elastically contacted with the heat radiating component 5 by the leaf spring 6b, the electromagnetic shield component 6 and the heat radiating component 5 can be contacted with high reliability even when vibration is applied. Therefore, electromagnetic shielding performance can be ensured.

Furthermore, in the case of a configuration in which a heat radiation component, which is a heavy object, is fixed to an electromagnetic shield component as in the prior art, it is necessary to increase the plate thickness of the electromagnetic shield component. In order to satisfy the vibration resistance performance, for example, FIG. As shown in b), it is necessary to extend the fastening piece 6c to the end of the electromagnetic shielding component 6 and fasten the screw 6d.
On the other hand, in the first embodiment, since the upper chassis 4 has a function of holding the heat radiating component 5 which is a heavy object, it is not necessary to increase the thickness of the electromagnetic shielding component 6. Therefore, the thickness of the electromagnetic shield component 6 can be reduced by reducing the plate thickness. By reducing the weight, it is possible to secure the vibration proof performance only by fixing the electromagnetic shield component 6 to the substrate 2 with the clip 7, and it is possible to fix it with a smaller area compared to the case of screwing. Therefore, the area of the substrate 2 can be reduced, and the electronic device can be reduced in size and weight.

  Further, by passing the protrusion 5 a of the heat dissipation component 5 through the opening 6 a of the electromagnetic shield component 6, the heat dissipation component 5 has a function of preventing the electromagnetic shield component 6 from coming off.

Here, a specific configuration example of the electronic device will be described.
FIG. 3 shows an exploded perspective view of the electronic device, and FIG. 4 shows a plan view of the electronic component 1 with the upper chassis 4 and the heat dissipation component 5 removed. In this example, the electromagnetic shielding component 6 is fixed to the substrate 2 using the clips 7-1 to 7-5, and the electronic components 1-1 to 1-3 are shielded to ensure the electromagnetic shielding performance.

  The heat dissipating component 5 is provided with a protrusion 5a-1 at a position facing the heat generating electronic component 1-1, and the protrusion 5a- at a position facing the heat generating electronic component 1-2, 1-3. 2 is protruding. By bringing the electronic components 1-1 to 1-3 and the protrusions 5a-1 and 5a-2 into contact with each other through the heat conducting component 8 and improving the heat dissipation performance, the heat dissipation component 5 can be reduced in size and weight.

  In addition, since there is a place where the board 2 and the lower chassis 3 are screwed near the electromagnetic shield component 6, the screwed piece 6c is used by using screws 6d-1 to 6d-3 instead of the clip 7 at that place. -1 to 6c-3 and the lower chassis 3 are fastened together. Thereby, even if it provides the to-be-fastened piece 6c-1 to 6c-3, it is possible to improve vibration proof performance, without narrowing the component mounting area of the board | substrate 2. FIG.

  As described above, according to the first embodiment, the electronic device is provided on the substrate 2 on which the electronic component 1 is mounted, the lower chassis 3 and the upper chassis 4 that accommodate the substrate 2, and the upper end surface of the electronic component 1. The heat-conducting component 8 is fixed to the upper chassis 4, and the heat-dissipating component 5 that contacts the upper end surface of the electronic component 1 through the heat-conducting component 8 and the side of the electronic component 1 are enclosed, and the lower end is fixed to the substrate 2. The upper end portion is configured to include the electromagnetic shielding component 6 that elastically contacts the heat radiating component 5. For this reason, it is not necessary for the electromagnetic shield component 6 to support the heat radiating component 5, the thin and light weight can be reduced, and the grounding area can be reduced, and the area of the substrate can be expected to be reduced. Moreover, since the electronic component 1 and the heat radiating component 5 can be directly brought into contact with each other via the heat conducting component 8, it is possible to expect a reduction in the size of the heat radiating component 5 due to an improved heat radiating effect. Due to these effects, even if the grounding area for fixing the electromagnetic shielding component 6 to the substrate 2 is reduced, the vibration resistance performance, electromagnetic shielding performance, and heat dissipation performance equivalent to the conventional one can be satisfied, and the entire electronic device is reduced in size and weight. Is possible.

  Moreover, according to Embodiment 1, since the leaf | plate spring 6b which elastically contacts the thermal radiation component 5 was formed in the upper end part of the electromagnetic shielding component 6, the thermal radiation component 5 and the electromagnetic shielding component 6 are made to contact with high reliability. And can secure electromagnetic shielding performance.

  Further, according to the first embodiment, the electromagnetic shield component 6 has the opening 6a that exposes the electronic component 1, and the leaf spring 6b is formed on the periphery of the opening 6a to make elastic contact with the heat dissipation component 5. The heat dissipating component 5 has a protrusion 5a that passes through the opening 6a and contacts the upper end surface of the electronic component 1 through the heat conducting component 8 in the electromagnetic shield component 6. For this reason, heat dissipation performance can be improved. Further, the heat radiation component 5 can have a function of preventing the electromagnetic shield component 6 from coming off.

  In addition, according to the first embodiment, the electronic device is configured to include the clip 7 that sandwiches the lower end portion of the electromagnetic shield component 6 on the substrate 2, so that the area for fixing the electromagnetic shield component 6 to the substrate 2 is reduced. Thus, the area of the substrate 2 can be reduced.

Embodiment 2. FIG.
FIG. 5 is a schematic diagram showing a cross-sectional structure of the electronic apparatus according to the second embodiment. The same or corresponding parts as those in FIGS.
In the second embodiment, instead of forming the leaf spring 6 b on the electromagnetic shield component 6, the electromagnetic shield component 6 and the heat dissipation component 5 are brought into elastic contact using the conductive elastic component 10. Examples of the conductive elastic component 10 include a gasket in which a core material is covered with a metal mesh.

  By sandwiching the conductive elastic component 10 between the electromagnetic shield component 6 and the heat dissipation component 5 and elastically contacting the electromagnetic shield component 6 and the heat dissipation component 5, the tolerance is large and the contact is unstable in the leaf spring 6b. In this case, even when the upper chassis 4 is deformed by the reaction force of the leaf spring 6b and when there is no space for forming the leaf spring 6b in the electromagnetic shield component 6, the electromagnetic shield component 6 is highly reliable. Can be brought into contact with each other, and electromagnetic shielding performance can be secured.

Embodiment 3 FIG.
6 and 7 are schematic views showing a cross-sectional structure of the electronic apparatus according to the third embodiment. The same or corresponding parts as those in FIGS. 1 to 4 are denoted by the same reference numerals and the description thereof is omitted.
In the third embodiment, an opening 4a is formed in the upper chassis 4 to which the heat dissipating component 5 is fixed, and a fan is attached to the opening 4a to cool the heat dissipating component 5, thereby efficiently dissipating heat. Improve. As the fan, for example, a blowing type axial flow fan 11 as shown in FIG. 6 or a side flow type sirocco fan 12 as shown in FIG. 7 may be used.

  In the case of the axial fan 11 shown in FIG. 6, if there is a shield (for example, the heat dissipating component 5) at the outlet, the noise will increase. On the other hand, in the case of the sirocco fan 12 shown in FIG. 7, the electronic component 1 can be efficiently cooled while suppressing the generation of noise. The axial fan 11 and the sirocco fan 12 may be properly used depending on the use of the electronic device. Further, a type of fan other than the axial fan 11 and the sirocco fan 12 may be used.

Here, a specific configuration example of the electronic device will be described.
8 is an exploded perspective view of the electronic device, FIG. 9A is a plan view of the electronic device, and FIG. 9B is a cross-sectional view taken along the line AA. In this example, the fan holder 13 that holds the sirocco fan 12 is attached to the upper chassis 4. Since the sirocco fan 12 sucks air not only from the lower chassis 3 side but also from the upper chassis 4 side, the board 14 can be fixed to the upper chassis 4 and cooled.

  As described above, according to the third embodiment, the electronic apparatus includes the fan that cools the heat radiating component 5, so that the heat dissipation performance can be improved efficiently.

  In the electronic device of the third embodiment, instead of forming the leaf spring 6b on the electromagnetic shielding component 6, the conductive elastic component 10 as described in the second embodiment is used, and the electromagnetic shielding component 6 is used. And the heat dissipating component 5 may be elastically contacted.

  In the first to third embodiments, the chassis that accommodates the substrate 2 is configured by the lower chassis 3 and the upper chassis 4 and the heat dissipation component 5 is fixed to the upper chassis 4. However, the present invention is not limited thereto. is not. Hereinafter, modified examples will be described with reference to FIGS. 10 and 11.

  When a significant heat dissipation performance is not required, as shown in FIG. 10, the heat dissipating component 5 made of aluminum having a high thermal conductivity or the like is replaced with an upper chassis 4 made of iron or the like having a low thermal conductivity. Reduce heat dissipation component 5. In this case, in order to provide the upper chassis 4 with a function as the heat radiating component 5, the upper chassis 4 is formed with a protrusion 4 b that protrudes toward the electronic component 1, and the protrusion 4 b is electronically connected via the heat conduction component 8. The upper chassis 4 and the electromagnetic shielding component 6 are brought into elastic contact with each other while being brought into contact with the component 1. Thereby, vibration resistance performance, electromagnetic shielding performance, and heat radiation performance can be satisfied while reducing the number of parts.

  Alternatively, when the demand for the function as a structural member is low, such as fixing other parts (for example, the axial fan 11 and the substrate 14 of the third embodiment) to the upper chassis 4, the upper chassis 4 is made of iron or the like. The chassis 4 can be replaced with a heat dissipating component 5 made of aluminum or the like having inferior strength. That is, the upper chassis 4 is reduced by fixing the heat dissipating component 5 to the lower chassis 3 as shown in FIG. Thereby, vibration resistance performance, electromagnetic shielding performance, and heat radiation performance can be satisfied while reducing the number of parts.

  As described above, when the chassis is configured by the box-shaped lower chassis 3 and the upper chassis 4 that covers the opening of the lower chassis 3, and the upper chassis 3 is configured by the heat dissipation component 5, the number of components can be reduced. Electronic devices can be made smaller and lighter.

  In the illustrated example, the leaf spring 6b is formed on the electromagnetic shield component 6. However, instead of the leaf spring 6b, the conductive elastic component 10 as described in the second embodiment is used, and the electromagnetic spring shown in FIG. The shield component 6 and the upper chassis 4 may be elastically contacted, or the electromagnetic shield component 6 and the heat dissipation component 5 of FIG. 11 may be elastically contacted.

  In addition to the above, within the scope of the invention, the invention of the present application can be freely combined with each embodiment, modified any component of each embodiment, or omitted any component in each embodiment. Is possible.

  As described above, the electronic device according to the present invention is reduced in size and weight while satisfying the vibration proof performance, electromagnetic shielding performance, and heat dissipation performance. For example, the electronic device is mounted on a vehicle. Suitable for use.

  1, 1-1 to 1-3 electronic components, 2,14 substrate, 3 lower chassis, 4 upper chassis, 4a opening, 4b protrusion, 5 heat dissipation component, 5a, 5a-1, 5a-2 protrusion, 6 Electromagnetic shield component, 6a opening, 6b leaf spring, 6c, 6c-1 to 6c-3 Fastened piece, 6d, 6d-1 to 6d-3 screw, 7, 7-1 to 7-5 clip, 8 heat conduction Parts, 10 conductive elastic parts, 11 axial fans, 12 sirocco fans, 13 fan holders.

Claims (7)

A board on which electronic components are mounted;
A chassis containing the substrate;
A heat conducting component provided on an upper end surface of the electronic component;
A heat dissipating component fixed to the chassis and in contact with the upper end surface of the electronic component via the heat conducting component,
An electronic apparatus comprising: an electromagnetic shielding component that surrounds a side of the electronic component, a lower end portion is fixed to the substrate, and an upper end portion elastically contacts the heat dissipation component.   The electronic device according to claim 1, wherein a leaf spring that elastically contacts the heat dissipation component is formed at an upper end portion of the electromagnetic shield component. Comprising a conductive elastic component sandwiched between the electromagnetic shielding component and the heat dissipation component;
The electronic device according to claim 1, wherein the electromagnetic shield component is in elastic contact with the heat dissipation component via the conductive elastic component. The electromagnetic shielding component has an opening that exposes the electronic component, and the periphery of the opening is in elastic contact with the heat dissipation component,
4. The heat radiating component has a protrusion that passes through the opening and contacts the upper end surface of the electronic component through the heat conducting component in the electromagnetic shielding component. Electronic equipment.   The electronic apparatus according to any one of claims 2 to 4, further comprising a clip that is fixed to the substrate and sandwiches a lower end portion of the electromagnetic shielding component.   The electronic device according to claim 2, further comprising a fan that cools the heat dissipation component.   The said chassis has a box-shaped lower chassis and the upper chassis which covers the opening of the said lower chassis, The said upper chassis is comprised by the said heat radiating component of Claim 1-6 characterized by the above-mentioned. The electronic device of any one of Claims.

Images